Maureen Koplow yesterday asked: “I was wondering if there’s any connection between the “dom” words, as in dominate, dominion, domicile, domestic, dome, domino, and the Latin word domini.”

Indeed, they are all related. They go back to a Proto-Indo-European root dom- “home, household” which developed semantically in at least two directions. One is toward larger buildings: dôme in French and duomo in Italian mean “cathedral”, i.e. the House of the Lord. Later dôme came to refer to that part of the Italian Duomo in Florence that distinguishes it from lesser buildings. It was at this point that English borrowed it.

The other semantic direction in which this root drifted was that of ownership of a house or household. The adjective, dominus “having a household or estate” went on to refer to the owner of an estate as lord in the original sense of estate owner. From there its sense expanded to the Lord of the universe, Lord in the religious sense.

Dominate goes back to a feudal sense of “owning a household or estate” at a time when those who lived and worked on an estate were dominated by the lord of that estate.

It is amazing how little the form of this root has changed given the immense changes in its meaning since the days of Proto-Indo-European 7-8,000 years ago. (Russian is an exception: dom still means “house” in Russian today.) That initial [d] should have become [t] in Germanic languages. If it did, that version of the root evaporated somewhere between Proto-Indo-European and today.